Wire printing apparatus having closed inking system

ABSTRACT

Ink is applied through a substantially closed system onto the surface of an engraved wheel which prints a legend or design onto a wire running tangentially against the wheel. A peristaltic pump delivers ink from a closed ink reservoir through a conduit formed with a discharge opening dimensioned to accommodate the periphery of the printing wheel which rotates in the conduit opening to receive a coating of ink. A fork-shaped plastic wiper removes excess ink from the wheel prior to engaging the wire. An applicator housing is formed with a drain to collect excess ink and return it via a conduit to the ink reservoir. The housing is spring-loaded to bear against the wheel and is mounted for movement as a unit to and away from the wheel to permit cleaning and/or changing of the wheel. The peristaltic pump is formed with a movable wall portion to relieve pressure from the conduit when the system is shut down in order to allow complete draining of the lines.

United States Patent 1 Brown et a1.

[75 Inventors: Charles P. Brown, Carlisle; Derwiu R. Eggleton, Concord, both of Mass. [73] Assignee: Riggs & Lombard, Inc., Lowell,

Mass.

[22] Filed: July 2, 1971 [21] Appl. No.: 159,224

[52] US. Cl. 101/37, 101/169, 101/363,

[51] '1nt,Cl.....B41t 17/10, F04b 43/12, 1341f 31/08 [58] Field of Search 101/36, 37, 366,

[561' References Cited UNITED STATES PATENTS 2,650,537 9/1953 Rosse 101/157 2,934,005 4/1960. Gemelli 101/366 X 3,111,897. 11/1963 Van Buskirk'.... 101/366 X 3,384,013 5/1968 King et a1. 101 350 1,833,133 11/1931 Stoessel 101/157 3,431,864 3/1969 Jones, Jr. 417/475 1,933,887 11/1933 Wood 101/351 2,898,849 8/1959 Gillies 101/37 2,278,387 3/1942 Wickwire,'Jr..... 101/157 2,631,532 3/1953 I l-larless 101/157 1 June 19, 1973 2,376,620 5/1945 Piazze l0l/l57 Primary ExaminerRobert E. Pulfrey Assistant Examiner -clifford D. Crowder Attorney-Oliver C. Morse, Gerald Altman and Richard J. Oates [5 7 ABSTRACT via a conduit to the ink reservoir. The housing is springloaded to bear against the wheel and is mounted for movement as a unit to and away from the wheel to permit cleaning and/or changing of the wheel. The peristaltic pump is formed with a movable wall portion to relieve pressure from the conduit when the system is shut down in order to allow complete draining of the lines.

8 Claims, 9 Drawing Figures Patented June 19, 1973 3,739,717

3 Sheets-Sheet 1 I/VVENTOR CHARLES P. BROWN DERWIN R. EGGLETON B) 7 I m 0&6?

ATTORNEYS Patented June 19, 1973 3,739,717

3 Sheets-Sheet 2 g lmllml' 66 IIVl E/VTOR CHARLES R BROWN DE-RWIN R. EGGLETON BYWVW Q1 1 ATTORNEYS Patented June 19, 1973 3,739,717

3 Sheets-Sheet 3 INVE/VTOR CHARLES P. BROWN 7 DERWIN R. EGGLETON By 7In4p 61m ATTORNEYS WIRE PRINTING APPARATUS HAVING CLOSED INKING SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to printing machinery and more particularly is directed towards a new and improved apparatus for printing designs and legends on a running strand such as insulated electric wire.

2. History of the Prior Art Insulated electric wires frequently will have printed thereon a legend such as manufacturers name, a design for coding purposes or some other printed indicia. Heretofore, the machinery employed to print on strands such as insulated wires involved an engraved wheel which rotated in an open trough filled or partially filled with ink. A wiper removed excess ink applied to the engraved portion of the wheel engaging the running wire. The use of an open trough of ink has not proven to be satisfactory insofar as the ink employed vaporizes quickly .in air with the result that the viscosity and the temperature of the ink in the trough changes as the machine is running, producing printing on the wire of an irregular quality. Furthermore, printing equipment of the foregoing type requires frequent cleaning to remove ink deposits that accumulate on the equipment. Also, in open type applicators excess ink flies off the rotating printing wheel, not only wasting ink but also spotting equipment, personnel as well as the wire.

A further disadvantage of present equipment is that the ink hardens rather quickly and, when a reel of wire is being replaced on the machine, the printing operation is stopped during the replacement operation. While the machine is shut down, the ink starts to coagulate on the wheel so that when the operation is resumed very irregular printing results.

Accordingly, it is an object of the present invention to provide improvements in machinery for printing on a running strand such as insulated electrical wire. A further object of this invention is to provide in an apparatus for printing of an insulated wire a substantially closed system for re-circulating ink against a printing wheel to maintain constant ink viscosity and temperature whether or not the machine is printing. Still another object of this invention is to provide an ink applicator for a wire printing machine of improved construction and design and one which is easily moved into and out of engagement with the wheel for servicing.

SUMMARY OF THE INVENTION ink applicator adapted to apply a continuous metered amount of ink onto the engraved periphery of the wheel, a peristaltic pump connected to the applicator through a conduit and adapted to pump ink from an enclosed ink supply to the applicator. The conduit is formed with a restricted discharge opening in the applicator to receive the periphery of the wheel with a drain for recovery of'the overflow. The applicator is movable into and out of engagement with the wheel and a spring-loaded arrangement maintains pressure contact between the applicator and the wheel. A fork-shaped wiper removes excess ink from the wheel prior to the printing operation..A peristaltic pump is provided to deliver pumping pressure to the conduit and deliver ink to the applicator. The pump is provided with a retractable portion which relieves pressure on the conduit when not in operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat schematic perspective view of an apparatus made according to the invention for printing on a running strand such as wire,

FIG. 2 is a view in front elevation showing two units made according to FIG. 1 for printing simultaneously on both sides of a running strand,

FIG. 3 is a detailed plan view showing the discharge end of the ink supply conduit,

FIG. 4 is a detailed side elevation of the printing wheel employed in the apparatus,

FIG. 5 is a detailed side elevation of the ink wiper employed in the invention,

FIG. 6 is a top plan view of the ink wiper,

FIG. 7 is a sectional side elevation of the applicator,

FIG. 8 is a front elevation of the peristaltic pump employed in the system, and,

FIG. 9 is a cross-sectional view taken along the line 9-9 of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBQDIMENT Referring now to the drawings and more particularly to FIG. 1, the apparatus is generally organized about a printing wheel 10 rotatably supported to a frame 12 and adapted to apply a legend, design, or other printing on a longitudinally running strand 14 of insulated wire or the like moving tangentially against the periphery of the wheel 10. The strand 14 is fed as from the spool 16 against the wheel, either vertically, horizontally or any other suitable angle, and, once it has been printed, the strand is passed through an oven (not shown) where the ink is dried and the strand is then wound-up on a take-up spool (not shown).

Operatively associated with the printing wheel 10 is an ink applicator 18 mounted to the frame 12 and adapted to apply a continuous coating of printing liquid such as ink to the periphery of the wheel 10 which is suitably engraved with the desired design, legend or the like. The applicator 18 receives a continuous flow of ink from a pump 20 through a conduit 22, the pump delivering the ink from an ink supply source such as a bottle 24 through a conduit 26. A return drain conduit 28 is connected between the bottle 24 and the applicator 18 to return excess ink to the bottle for re-circulation. The speed of the pump and the ink flow is controlled by means of a motor 30 drivingly connected to the pump 20, the speed of the motor 30 being regulated by a controller 32.

THE APPLICATOR The applicator 18 in conjunction with the pump is adapted to apply a continuous metered amount of ink onto the periphery of the printing wheel 10. The wheel 10 typically is in the form of a hard metal disc the peripheral edge of which is formed with a concave annular groove 34, as best shown in FIG. 4 to conform with the cylindrical configuration of the wire 14. Other profiles obviously may be used depending upon the shape of the strand. The concave periphery is engraved with the design or legend to be imprinted on the wire and the applicator serves to apply ink to the periphery with excess ink being removed by a wiper 36 prior to contact with the wire. Typically, the wheel is freewheeling, rotation being imparted to the wheel by means of the wire 14 which is drawn against the engraved edge and is in pressure contact therewith as by a matching printing wheel 10' (FIG. 2) which prints on the opposite side of the wire 14. Where the wire is to be printed along one side only, an idler pressure roller may be positioned oppositely the wheel 10 to provide a pressure contact between the wire and the wheel. Alternatively, the wire may wrap slightly about the wheel.

The applicator 18 includes a U-shaped tray or base 38 carried by a pair of spaced parallel links 40 and 42 pivotally mounted to the frame 12 by pivot pins 44 and 46 and pivotally connected to the base 38 by pivot pins 48 and 50. The link 42 extends beyond its pivot pin 46 and is provided at its upper end with a screw 52 which, in operative position, is threaded into a cooperating tapped hole formed in the front face of the frame 12. In the position illustrated in FIG. 1, with the screw 52 threaded into its tapped socket, the link 42 will be locked in the position shown with the applicator 18 in its operating position with respect to the printing wheel 10. The applicator 18 is moved out of operating engagement with the wheel 10 by unscrewing the screw 52 from its socket to permit the base 38 of the applicator 18 to swing about the pins 44 and 46 away from the wheel 10. In this fashion, the wheel 10 may be readily replaced to change printing designs or legends as desired. The applicator is returned to its operative position once the wheel is replaced by merely swinging it back into the position shown and securing the screw 52 in its hole.

The base 38 carries an applicator housing 54 which pivotally engages the base 38 by means of a pivot pin 56 at its lower right-hand corner as viewed in FIG. 1, the housing being urged normally upwards in a clockwise direction by means of a spring-loaded screw 58 threaded up through the bottom wall of the base 38 to engage the bottom wall of the housing 54 at the lower left-hand side thereof. This serves to maintain pressure contact between the applicator and the wheel during operation.

The applicator housing 54 is formed with an opening 60 in its upper end of a size and configuration to accommodate a chordal section of the wheel 10 with a minimum amount of clearance to reduce contact between the air and the ink. The applicator housing 34 is formed with an internal cavity 62 which serves as a drain for excess ink fed in through the conduit 22 and connects with the return line 28 through a suitable coupling. The inlet ink conduit 22 extends in through the end of the applicator housing and into the cavity 62 in position to make tangential contact with the wheel 10 which rotates into the applicator housing through the opening 60. The end of the conduit 22 is closed as by a plug 64 but is formed along its upper surface with a slit opening 66 (FIG. 3) of a length and width sufficient to accommodate a small chordal section of the wheel 10 which rotates into the slit opening to receive a coating of ink pumped through the conduit 22. A slight amount of clearance is provided between the edges of the slit opening 66 and the wheel to permit any excess ink to bubble into the cavity 62 to be returned through the drain line 28 to the bottle 24.

Directly after the wheel picks up its coating of ink, it moves against the wiper 36 which removes excess ink,

leaving ink only in the engraved portions of the wheel prior to engaging the wire 14. The wiper 36, in the preferred embodiment, is fabricated from a durable plastic having a low co-efficient of friction such, for example, a plastic sold under the trademark Delrin" or a plastic such as sold under the trademark Teflon". The wiper typically is of generally cylindrical configuration formed with a bifurcated upper end with leg portions 66 and 68 (FIG. 5) extending upwards on either side of a transverse slot 70 formed in the end of the wiper 36. The slot 70 has a width corresponding with the thickness of the wheel 10 and the legs 66 and 68 serve to wipe the marginal outer edges of the wheel while the beveled upper edge 72 formed by the slot 70 wipes the concave peripheral edge of the wheel. In practice, the beveled edge 72 may be cut to match the contour of the wheel or may be cut straight initially since the wiping edge will conform to the contour of the wheel edge. The wiper 36 is mounted for a vertical adjustment by means of a screw 74 for periodically raising the wiper as the wiping edge 72 becomes worn.

TI-IE PUMP Referring now more particularly to the pump 20, in the preferred form of the invention a peristaltic pump is employed and in the illustrated embodiment it is comprised of fixed spaced opposing guide walls 76 and 78 and a fixed center guide 80 therebetween. The guides 76, 78 and 80 form a guideway for a length of flexible tubing 82 connected to the conduits 22 and 26. The tubing 82 is passed between a rotatable pump member 84 and a cooperating block 86 formed with a semi-cylindrical trough 88 to receive the member 84. The rotatable member 84, which in the illustrated embodiment is a two-stage pump component, is comprised of a shaft 90 drivingly connected to the motor 30 and carrying two or more spaced circular plates 92 and 94 fixed to the shaft 90 and rotatably supporting therebetween a pair of offset rollers 96 and 98 spaced 180 apart.

It will be understood that when the shaft 90 is rotated by the motor the circular plates 92 and 94 will rotate about the shaft axis carrying the offset rollers 96 and 98 which will squeeze against the tubing 82 looped between the rollers and the semi-cylindrical surface of the trough 88 formed in the block 86. Each of the rollers will flatten the tubing at its point of contact and produce a rolling, squeezing action against the tube to move along ink or other liquid within the tubing in a substantially friction-free pumping action. In the illustrated embodiment, the pump is provided with a third circular plate 100 which cooperates with the plate 94 to support another pair of rollers 102 and 104 for a second pumping stage, the rollers of the second stage being positioned 90 out of phase with the rollers of the first stage whereby, with the tubing looped first about one stage and then about the: other stage, a substantially continuous pumping action will be produced in the tubing. Ink flowing through the tubing is controlled by the speed of rotation of the shaft as determined by the motor 30. Typically, the motor 30 is a DC motor,

its speed being selectively regulated by the controller The block 86, which in operating position, is shown in full line in FIGS. 1 and 8 is adapted to be lowered out of working engagement with the rollers when the printing operation is to be stopped as at the end of a working day. The block 86 is moved by means of a lead screw 106 pinned at its upper end to the block and threaded to a nut 108 resting on a shoulder 109. Rotation of the nut in one direction or the other will move the lead screw 106 up and down to thereby move the block 86 into or out of operating position. Guide pins 110 and 112 are provided on either side to guide the block along a straight path and insure proper seating of the block when in its raised operating position. The purpose of providing a movable section of the pump, namely the block, is to relieve pressure on the tubing when the system is shut down. With pressure relieved, all of the ink or other fluid within the lines may be drained fully back into the bottle 24. It is desirable to maintain the conduits as clean as possible so that residue will not build up and clog the lines. In practice, when shutting down the machine, the ends of the conduits 26 and 28, which may be connected to a common stopper 114, may be transferred to a bottle of solvent, thinner or the like and the pump operated to circulate the thinner through the pump, tubes'and applicator to thoroughly clean the system before draining the line.

Since the pumping action is independent of the printing operation, the pump may be kept running to prevent coagulation and maintain constant viscosity and temperature while a reel 16 is being replaced on the machine. Thus, when one reel has been fed completely through the machine and its wire fully printed from end to end, the reel may be replaced without stopping the pumping action. When a fresh strand is fed through the machine, the printing will start off cleanly and sharply and all printing done along the length of the wire will be of uniform quality, even if the machine should be stopped before the end of the run. The continuous recirculation of the ink provides an almost essentially closed system affording a constant, homogenous ink feed resulting in constant ink printing quality.

Having thus described the invention what we claim and desire to obtain by Letter Patent of the United States is:

1. Apparatus for printing on a running strand such as wire or the like, comprising a. a support,

b. a rotatable printing wheel mounted to said support and formed with peripheral printing indicia,

c. means for guiding said strand against the printing portion of said wheel,

d. a substantially closed applicator cooperatively positioned adjacent said wheel and formed with an opening adapted to receive a portion of said wheel,

e. a peristaltic pump connected to a supply of printing liquid and to said applicator for delivering a flow of said liquid through said applicator against said wheel, and,

f. adrain conduit connected to said applicator and said supply for returning excess liquid to said sup- P y.

g. said applicator including a tubular conduit connected to said pump and extending into said applicator in tangential relation to said wheel, said conduit being formed with a restricted slot opening to receive a chordal portion of said wheel for direct application of liquid thereon,

h. said applicator including a wiper in wiping contact with the printing portion of said wheel to remove excess liquid therefrom.

2. Apparatus according to claim 1 wherein said wiper is a plastic rod and formed with a wheel engaging diagonal slot diametrically across one end thereof for wiping excess liquid from said wheel.

3. Apparatus according to claim 1 including means mounting said applicator to said support for movement to and away from said wheel and locking means for locking said applicator in operative position against said wheel.

4. Apparatus according to claim 3 wherein said mounting means includes a pair of spaced parallel links pivoted to said support and pivotally carrying said applicator.

5. Apparatus according to claim 4 wherein said locking means is a member adapted to engage one of said links to said support to prevent pivoting of both of said links.

6. Apparatus according to claim 1 including control means connected to said pump for selectively varying the speed thereof.

7. Apparatus according to claim 1 wherein said pump includes at least one roller, drive means connected to said roller for rotating said roller about an offset axis, a stationary wall formed with an arcuate surface disposed in closely spaced relation to said roller and a length of flexible, resilient tubing disposed between .said roller and said surface and connected to said supply of liquid whereby liquid will be pumped through said tubing upon rotation of said roller, said wall and said roller being relatively movable with respect to one another for selectively varying the spacing between said wall and roller.

8. Apparatus according to claim 1 wherein one portion of said applicator is hinged to another portion thereof and a resilient member is disposed between said portions for urging said one portion towards said wheel. 

1. Apparatus for printing on a running strand such as wire or the like, comprising a. a support, b. a rotatable printing wheel mounted to said support and formed with peripheral printing indicia, c. means for guiding said strand against the printing portion of said wheel, d. a substantially closed applicator cooperatively positioned adjacent said wheel and formed with an opening adapted to receive a portion of said wheel, e. a peristaltic pump connected to a supply of printing liquid and to said applicator for delivering a flow of said liquid through said applicator against said wheel, and, f. a drain conduit connected to said applicator and said supply for returning excess liquid to said supply, g. said applicator including a tubular conduit connected to said pump and extending into said applicator in tangential relation to said wheel, said conduit being formed with a restricted slot opening to receive a chordal portion of said wheel for direct application of liquid thereon, h. said applicator including a wiper in wiping contact with the printing portion of said wheel to remove excess liquid therefrom.
 2. Apparatus according to claim 1 wherein said wiper is a plastic rod and formed with a wheel engaging diagonal slot diametrically across one end thereof for wiping excess liquid from said wheel.
 3. Apparatus according to claim 1 including means mounting said applicator to said support for movement to and away from said wheel and locking means for locking said applicator in operative position against said wheel.
 4. Apparatus according to claim 3 wherein said mounting means includes a pair of spaced parallel links pivoted to said support and pivotally carrying said applicator.
 5. Apparatus according to claim 4 wherein said locking means is a member adapted to engage one of said links to said support to prevent pivoting of both of said links.
 6. Apparatus according to claim 1 including control means connected to said pump for selectively varying the speed thereof.
 7. Apparatus according to claim 1 wherein said pump includes at least one roller, drive means connected to said roller for rotating said roller about an offset axis, a stationary wall formed with an arcuate surface disposed in closely spaced relation to said roller and a length of flexible, resilient tubing disposed between said roller and said surface and connected to said supply of liquid whereby liquid will be pumped through said tubing upon rotation of said roller, said wall and said roller being relatively movable with respect to one another for selectively varying the spacing between said wall and roller.
 8. Apparatus according to claim 1 wherein one portion of said applicator is hinged to another portion thereof and a resilient member is disposed between said portions for urging said one portion towards said wheel. 